People at Goldman Sachs have a sense of humour. Bloomberg reports that Goldman executives have been hiring actors to perform ‘hidden camera pranks’ on senior partners who are seemingly accepting of such silliness.

The latest such prank, orchestrated by Goldman COO Gary Cohn involved Alison Mass, co-head of Goldman’s Financial Sponsor (private equity) division and David Dase, head of the telecoms media and technology group. The two bankers were filmed during a pitch by a supposed entrepreneur who claimed to have developed a method of purifying filthy water. The entrepreneur (actually an actor), reportedly held a cup of dirty water and insisted it was safe drink before taking a sip and urging the bankers to do the same. This, says Bloomberg, was just the latest, ‘in a series of hidden-camera pranks targeting partners,’ later played with much hilarity to other people at the firm.

Such tricks seem to be nothing new. When Greg Smith went rogue and wrote a book about his experiences at Goldman in 2012, he reported similar such goings on. Back then, Smith said a senior partner set up a prank interview and employed a professional actor to impersonate a major hire. During the interview, the actor behaved like a ‘complete asshole’, interrupting the interviewers and putting his feet up on the desk. When the Goldman interviewers asked him for his goals, he said he’d like two helicopters – one at the top and one at the bottom of a ski slope and when asked whether he had any questions for them, the actor said, ” I have a lot of mental health problems. How’s the firm’s psychiatric coverage.”

You could argue that Goldman is training its senior staff in the art of incredulity. Or maybe partners are simply encouraged not to take themselves too seriously. Either way, it’s hard to imagine similar tricks being played over at Antony Jenkins’ Barclays, where sanctimony reigns.

Separately, now that Thomas Piketty’s book has elevated academic economists to the status of minor deities, it’s worth considering how much you can earn from such tomes. Piketty is expected to sell more than 200,000 copies of his book in just a few months (maybe more at his current rate of success), making himself a six (or maybe seven) figure sum in the process. But it’s not just Gallic economists who can make good money out of business writing. The Sunday Times interviewed Ha-Joon Chang, a Cambridge (UK)-based Korean economist and author who’s written two mass market books (’23 Things They Don’t Tell You About Capitalism’ and ‘Economics a User’s Guide’) from which he made six figure sums. Chang has also just received an advance of £110k for his new, as yet unnamed, book. It’s not quite the $1.5m advance that Greg Smith reportedly got for his book on Goldman Sachs, but there is clearly money in finance writing for anyone who wants to leave banking or earn extra money at the weekends.

Meanwhile:

Sally Boyle, head of human capital management for Emea at Goldman Sachs, said: “In years to come we’ll be talking about mindfulness as we talk about exercise now.” (Financial Times)

JPMorgan thinks its second quarter trading revenues will fall another 20%. (Telegraph)

“It is a terrible thing to be an also-ran in this business,” observes an executive at one Wall Street bank. That is where Barclays finds itself. (Financial Times)